1. Field of the Invention
The field of art to which this invention pertains includes that of gear reduction drives; more specifically, to drive mechanisms for rotating a member such as for example a vehicle wheel.
2. Description of the Prior Art
Single wheel drives for vehicles are well-known and can generally be divided into planetary gear drives and cone pulley drives. Both of these drives present a number of disadvantages in that they are generally bulky and project axially outwardly from the vehicle whose wheels they are to drive. The sometimes excessively long axial dimensions of these drive units are due to their structural elements which include the driving motor, service and parking brakes along with multi-step reduction gearing. The excessive space occupied by many of the prior art units is of particular disadvantage when these wheel drives are used for fork lift trucks and the like where overall width dimensions are preferably kept to an absolute minimum in order to maximize maneuverablilty.
It is therefore desirable to provide wheel drive mechanisms that will not only have increased life expectancies over the prior art units, but also permit the entire gearing unit to be mounted within the wheel rim; permit ready servicing of the integral brake mechanism; are relatively economical to manufacture; and generally characterized by simplicity and ease of assembly and disassembly.